Despite being unbeaten on their travels this season, Forest have lost three times at the City Ground.
Earnshaw remains a doubt with a pelvic injury which forced him to miss the trip to Plymouth Argyle on Sunday.
Forest also have concerns over the fitness of Kelvin Wilson, who was withdrawn during the second half against the Pilgrims - his first league game of the season - with severe cramp in both legs.
Davies has no further new injury worries for Wednesday night's Championship clash, although Julian Bennett and James Perch continue to be long-term absentees.
